bviTouch lets blind and visually impaired users explore images on screen
by providing musical tones to represent the colors under their finger as they move them
about the image.

All images on a mobile device screen are composed of individual pixels (picture elements) that
contain some combination of the colors red, green and blue. bviTouch assigns a low pitch musical
tone to the red color, a high pitch musical tone to the blue color, and an intermediate pitch tone
to the green color. As the user touches the screen of an image, the app reads the colors in the
pixels under the finger and renders them into a combined audio playback that, with practice, can
be used by a bvi individual to explore the content of the images.

There are three sections to the app. These are discussed in greater detail below.

Tutorial SectionContains basic images and instructions that illustrate the operation of the bviTouch system.

Sample Images SectionContains images of many subjects to help the user familiarize themselves with
the operation of the bviTouch system, and to experience the exploration of real images.

My Images SectionAllows the user to select images (photos) from those that are already stored on the mobile device
and explore them using the bviTouch system.

YouTube Video
Introduces bviTouch App, which allows blind users to explore images with touch by providing musical tones to
represent colors as they move their fingers about images on mobile devices. Video suitable for review by both
sighted and blind/visually impaired users.

YouTube Video
Illustrates bviTouch App in operation, showing exploration by touch
of a number of different image types included in the app. Video suitable for sighted associates of blind
and visually impaired users, for use as examples and a guide to the use of the app.

Some Helpful Hints

The hints and instructions provided on this page are also provided in spoken form
within the operation of the app.

Though the app works satisfactorily with mobile device speakers, the best results are obtained
by the use of headphones, which provide greater clarity and audio fidelity.

The app can be used either with or without VoiceOver activated. The vocalizations of
the various instructions and descriptions are the same either way. This aspect of the app
recognizes that, in some cases, a sighted user may be assisting a bvi user in navigating the
app, and the sighted user may not be as facile with VoiceOver as the bvi user.

If VoiceOver is active and the speech rate needs to be adjusted, the user will have to
exit the app and adjust the VoiceOver speech rate in settings.

If VoiceOver is not active and the speech rate needs to be adjusted, the user can make a
quick single-finger swipe up on the Main Screen to enter a speech rate setting mode, and then
place their finger on the screen and move it left and right to select a suitable speech rate.

The best experience with the app is with the mobile device used in landscape orientation.
with the long side horizontal and the short side vertical. It will work in portrait mode, but
the images presented are much larger in landscape mode.

Images are presented in the lower 90% of each screen.

There are buttons at the top of the screens, but these are not activated by VoiceOver.
This is part of the visual interface that sighted users can use if VoiceOver is not activated.

Some of the instructions and descriptions in the app are fairly long. If the user wants to
stop the speech, they can make a quick single-tap to stop it. Another quick single-finger
tap will restart the speech from the beginning.

While the finger gestures that the app recognizes are similar to those of VoiceOver, the nature
of the app requires that some VoiceOver gestures will not be recognized.

Navigation (and other) gestures

All gestures recognized by the app are single-finger gestures.
Tap and swipe gestures should be performed very quickly.

Single tap - used to stop or restart speech.

Swipe down - generally used to navigate into the different app sections.

Swipe up - generally used to navigate out of the different app sections.

Swipe Right - used to navigate to the next image in a section.

Swipe Left - used to navigate to the prior image in a section.

Explore by Touch - user places finger on image screen and moves it about,
while the app plays the musical tones that correspond to the red, green
and blue content of the pixels under the user's finger.

Navigation gestures by section

While on the Main Screen (the opening screen):

Single tap - stop or restart speech.

Swipe down on left side of screen - enter the Tutorial Section.

Swipe down in middle of screen - enter the Sample Images Section.

Swipe down on right side of screen - enter the My Images Section.

Swipe up - if VoiceOver is not active, enters a mode that allows the
speech rate to be adjusted. The user makes a swipe up on the Main Screen
to enter a speech rate setting mode, and then places their finger on
the screen and moves it left and right to select a suitable speech rate.

While in the Tutorial Section:

Single tap - stop or restart speech.

Swipe right - go to the next screen in the Tutorial section.

Swipe left - go to the prior screen in the Tutorial section.

Swipe up - return to the Main screen.

Swipe down - enters a mode that allows the user to quickly navigate
among the various images in the section. This can be useful if a user
has already been through the section, and wants to quickly return to
a particular image within it. The user makes a swipe down on the image
to enter the selection mode, and then places their finger on
the screen and moves it left and right to hear the titles of the tutorial
images. The user stops (lifts finger) when they have found or are near
the desired image.

Explore by Touch - user places finger on image screen and moves it about,
while the app plays the musical tones that correspond to the red, green
and blue content of the pixels under the user's finger.

While in the Sample Images Section:

Single tap - stop or restart speech.

Swipe right - go to the next screen in the Sample Images section.

Swipe left - go to the prior screen in the Sample Images section.

Swipe up - return to the Main screen.

Swipe down - enters a mode that allows the user to quickly navigate
among the various images in the section. This can be useful if a user
has already been through the section, and wants to quickly return to
a particular image within it. The user makes a swipe down on the image
to enter the selection mode, and then places their finger on
the screen and moves it left and right to hear the titles of the sample
images. The user stops (lifts finger) when they have found or are near
the desired image.

Explore by Touch - user places finger on image screen and moves it about,
while the app plays the musical tones that correspond to the red, green
and blue content of the pixels under the user's finger.

While in the My Images Section:

Single tap - stop or restart speech.

Swipe right - go to the photo selection mode on the mobile device.
This will allow the user to select a photo from those that have already
been stored on the mobile device.

If the user exits the photo selection process, the app returns to the
Main screen.

Explore by Touch - once a photo has been selected, the user can explore
it by touch and hear the musical tones representing the content of the photo.

While a selected photo is being explored, the user can perform another
swipe right gesture to select and explore a different photo.